2012 Global Temperatures

[WeatherRusty]

What if the facts and evidence support legitimate fear about the future of the planet and humanity?

You are basically saying that if you are afraid or worried, you must be wrong.

This is exactly the point. It is the inherent uncertainty as to the full impact AGW will have that is most disconcerting. The scientifically supported possibilities and probabilities cover a broad range of potential. Skeptics and luke warmers are betting on the lower range of those potentials being more likely, when the actual science can not differentiate the likelihood between greater or lesser impact.

All we know for sure is that we are heading in a dangerous direction. The science assures us the long term warming will continue.

[tacoman25]

Right. In the early 1920's to 1940's, natural variability had a large chunk of responsibility for a distinctly positive trend. However, natural variability is currently acting to force a negative trend in the last 10 years, but the AGW signal is masking it completely (which is why using 10 years for climate trends in erronous). My point is, that the AGW signal is generally well understood in the context of natural forcing. Therefore, the consensus of climate scientists sounding the "alarm" probably should not be ignored.

I think there needs to be a balance. Both skeptics (or deniers) and AGW-awareness proponents (or alarmists) can read too much into short term trends, and false extrapolations/assumptions can be made. The bottom line is that there is still a lot we don't know about the climate system, but it is clear it is retaining more energy/warmth thanks to increased GHG, and it is also clear that natural variation can have a large effect on decadal trends, and enhance or mask the underlying AGW signal. The warming from the late 1970s to the early 2000s was enhanced by natural cycles. The early 2000s to present has seen the warming masked by natural factors.

[The_Global_Warmer]

It seems remarkable that some here don't understand the "precautionary principle" involved with prospective changes due to AGW. It is a bit like the Hippocratic Oath - "First, do not harm".

Yes, it is still impossible to prove apodictically that AGW will cause specific calamitous things to occur at specific times in the future. But the severity of the possible (and increasingly likely) consequences of AGW to all of us make it necessary to take out a bit of insurance against these consequences by curbing emissions - this is something we DO know enough to do. It is a prudent, conservative policy.

Given the urgency, those who minimize and even ridicule this need are worse than irritating.

What if the facts and evidence support legitimate fear about the future of the planet and humanity?

You are basically saying that if you are afraid or worried, you must be wrong.

It's confusing as well. In our current climate we have seen what small changes have done to the crysophere.

But people who admit they think we will warm 1-2C by 2100, and more likely 2-3c in the N.H. and more likely 4-8C in the arctic are not worried about an ice free arctic, or how that will effect Greenland which is already being effected big time by a climate much cooler than the one already in the works.

We are sold on 475ppm of co2, this will help push methane well over 2500ppb at least by this time because of so much coming from so many sources locked up in the permafrost, arctic, and so on.

It's hard to imagine now, but when the arctic is near ice free in early August large HP's can form, like say a sprawling one forms to the SW of Greenland and ushers 15-20C 850s into Greenland during peak melt under sunny skies, nothing like 75-80F air on the SW side being slammed into the ice pack for some waterfall melting.

Temperatures reached 20C in the Beaufort Sea, I mean, come on!

So later on we spend trillions trying to clean this up because we apparently do not know enough about it now except it's projected to be bad period.

That sounds like stupidity and terrible leadership.

We should be like, well just encase let's stop this madness.

[ORH_wxman]

What if the facts and evidence support legitimate fear about the future of the planet and humanity?

You are basically saying that if you are afraid or worried, you must be wrong.

If they did, then there would be a lot of reason to fear. But the facts do not support that at the moment. A lot of theory allows for that type of possibility, but facts do not support it yet.

The facts thus far (not opinion) support a gradually warming climate and gradually rising sea level. Theory suggests that we may see temperature rise accelerate and sea level rise accelerate, but that is yet to be supported by factual observations.

And no, there is reason to worry...but worrying and fear mongering are not the same thing.

[PhillipS]

What does everyone think of this interesting new paper by Solomon and Polvani? It suggests that stratospheric cooling is mostly due to ozone depletion. Quite interesting.

http://www.agu.org/p...2JD017719.shtml

This also agrees with Liu and Weng 2009 that stratospheric temperature declines may be mainly due to Ozone Depletion, since they found a complete reversal in stratospheric temperature trends starting from 1995.

Thank you for sharing that paper - you're right, it is interesting. Using Google Scholar I found several similar papers that support the central hypothesis.

Of course the next question is - what is causing the ozone depletion? Here is a recent paper, Portmann et al 2012, on just that topic that implicates anthropogenic nitrous oxides at the primary culprit. Here is their abstract:

The effects of anthropogenic emissions of nitrous oxide (N

₂

O), carbon dioxide (CO

₂

), methane (CH

₄

) and the halocarbons on stratospheric ozone (O

₃

) over the twentieth and twenty-first centuries are isolated using a chemical model of the stratosphere. The future evolution of ozone will depend on each of these gases, with N

₂

O and CO

₂

probably playing the dominant roles as halocarbons return towards pre-industrial levels. There are nonlinear interactions between these gases that preclude unambiguously separating their effect on ozone. For example, the CH

₄

increase during the twentieth century reduced the ozone losses owing to halocarbon increases, and the N

₂

O chemical destruction of O

₃

is buffered by CO

₂

thermal effects in the middle stratosphere (by approx. 20% for the IPCC A1B/WMO A1 scenario over the time period 1900–2100). Nonetheless, N

₂

O is expected to continue to be the largest anthropogenic emission of an O

₃

-destroying compound in the foreseeable future. Reductions in anthropogenic N

₂

O emissions provide a larger opportunity for reduction in future O

₃

depletion than any of the remaining uncontrolled halocarbon emissions. It is also shown that 1980 levels of O

₃

were affected by halocarbons, N

₂

O, CO

₂

and CH

₄

, and thus may not be a good choice of a benchmark of O

₃

recovery.

So between anthropogenic GHGs, anthropogenic nitrous oxides, and anthropogenic halocarbons we are really trashing the Earth's atmosphere.

[nzucker]

Right. In the early 1920's to 1940's, natural variability had a large chunk of responsibility for a distinctly positive trend. However, natural variability is currently acting to force a negative trend in the last 10 years, but the AGW signal is masking it completely (which is why using 10 years for climate trends in erronous). My point is, that the AGW signal is generally well understood in the context of natural forcing. Therefore, the consensus of climate scientists sounding the "alarm" probably should not be ignored.

Natural variability is only creating a small negative trend; it's not as if we have natural conditions similar to the Little Ice Age. The PDO didn't go negative until 2007, we had a very strong El Niño in 09-10, volcanic activity has been extremely low, and the solar minimum just started in the last few years, with the only period of really low sunspots being 2008. If this reduced the warming trend to around 0.03C/decade, what can a strongly negative forcing from natural variability do?

[nzucker]

It's confusing as well. In our current climate we have seen what small changes have done to the crysophere.

It's hard to imagine now, but when the arctic is near ice free in early August large HP's can form, like say a sprawling one forms to the SW of Greenland and ushers 15-20C 850s into Greenland during peak melt under sunny skies, nothing like 75-80F air on the SW side being slammed into the ice pack for some waterfall melting.

The Arctic warming is out of step with the "small changes," not necessarily a reflection of them. With GISS only showing a warming of about 0.03C/decade since 2002 (slightly more since 2000), the nearly 1C/decade change in the Arctic must have less to do with anthropogenic climate change and more to due with pure chance. I'm not saying that anthropogenic climate change hasn't started some feedback processes that warm the arctic, but a lot of it has been luck with all the summers since 2007 having a predominately -AO/-NAO pattern, and a strong one at that.

Also, you don't really get 20C 850s in Greenland. Put the pipe and MS Paint colors away. During Greenland's warm spells this summer, 850s weren't even 10C in most cases. Certainly not close to 20C. Alaska can get warmer than the Eastern Arctic, which has a large ice sheet and is affected by fewer intrusions of continental air.

[csnavywx]

The Arctic warming is out of step with the "small changes," not necessarily a reflection of them. With GISS only showing a warming of about 0.03C/decade since 2002 (slightly more since 2000), the nearly 1C/decade change in the Arctic must have less to do with anthropogenic climate change and more to due with pure chance. I'm not saying that anthropogenic climate change hasn't started some feedback processes that warm the arctic, but a lot of it has been luck with all the summers since 2007 having a predominately -AO/-NAO pattern, and a strong one at that.

Also, you don't really get 20C 850s in Greenland. Put the pipe and MS Paint colors away. During Greenland's warm spells this summer, 850s weren't even 10C in most cases. Certainly not close to 20C. Alaska can get warmer than the Eastern Arctic, which has a large ice sheet and is affected by fewer intrusions of continental air.

We're missing a critical element in this discussion with the impact of aerosols. I've mentioned this in another thread on this sub-forum, but it may be beneficial to cross-post in this thread. In past analyses, the aerosol direct and indirect effects were responsible for a large offset to GHG forcing (with a large uncertainty, but most analyses falling between -1 and -2 W/m2). High growth rates of coal consumption in Asia (all of which fall outside of tougher European and American standards) has no doubt resulted in significant increases in aerosol loading. The recent deployment of SO2 scrubbers by the PROC and slowing GNP growth rates may signal a relatively-near term abatement of the effect.

Aerosol forcing via tropospheric loading and stratospheric entrainment is significant.

[nzucker]

We're missing a critical element in this discussion with the impact of aerosols. I've mentioned this in another thread on this sub-forum, but it may be beneficial to cross-post in this thread. In past analyses, the aerosol direct and indirect effects were responsible for a large offset to GHG forcing (with a large uncertainty, but most analyses falling between -1 and -2 W/m2). High growth rates of coal consumption in Asia (all of which fall outside of tougher European and American standards) has no doubt resulted in significant increases in aerosol loading. The recent deployment of SO2 scrubbers by the PROC and slowing GNP growth rates may signal a relatively-near term abatement of the effect.

Aerosol forcing via tropospheric loading and stratospheric entrainment is significant.

I don't disagree that aerosols may be playing a role, but I think the PDO shows a more immediate and discernible causation. You can see on this graph that the last spike in global temperatures was when the PDO was at the end of its positive phase, and that the lack of global warming since 2002 (only .03C/decade) shows up very well in this graph as linked to the low PDO index:

[ORH_wxman]

We're missing a critical element in this discussion with the impact of aerosols. I've mentioned this in another thread on this sub-forum, but it may be beneficial to cross-post in this thread. In past analyses, the aerosol direct and indirect effects were responsible for a large offset to GHG forcing (with a large uncertainty, but most analyses falling between -1 and -2 W/m2). High growth rates of coal consumption in Asia (all of which fall outside of tougher European and American standards) has no doubt resulted in significant increases in aerosol loading. The recent deployment of SO2 scrubbers by the PROC and slowing GNP growth rates may signal a relatively-near term abatement of the effect.

Aerosol forcing via tropospheric loading and stratospheric entrainment is significant.

I havent gotten to read all the papers you linked yet, but in skimming a couple I still haven't seen a good explanation for the sharp rise in global temps post-1976 PDO shift that would support aerosols being more important than something like the PDO. I think the explanation for their effect on global temps is sound, however, the magnitude of their effect may be overstated.

But I will read all the papers you linked in full before coming to that full conclusion. Perhaps there are some feasible explanations that I haven't read yet.

[csnavywx]

To add another data point to the chart I posted above:

China's coal consumption from 2010 to 2011 grew a whopping annualized growth rate of 9.4% (or up from 3.69 to 4.05 Billion Short Tons). That's also up 50% from 2007's level of 2.7 BST. Explosive growth. Amazing what exponential rates in a large country will do.

[The_Global_Warmer]

The Arctic warming is out of step with the "small changes," not necessarily a reflection of them. With GISS only showing a warming of about 0.03C/decade since 2002 (slightly more since 2000), the nearly 1C/decade change in the Arctic must have less to do with anthropogenic climate change and more to due with pure chance. I'm not saying that anthropogenic climate change hasn't started some feedback processes that warm the arctic, but a lot of it has been luck with all the summers since 2007 having a predominately -AO/-NAO pattern, and a strong one at that.

Also, you don't really get 20C 850s in Greenland. Put the pipe and MS Paint colors away. During Greenland's warm spells this summer, 850s weren't even 10C in most cases. Certainly not close to 20C. Alaska can get warmer than the Eastern Arctic, which has a large ice sheet and is affected by fewer intrusions of continental air.

I didn't say you could, I was referencing the future, hence when the arctic is nearly ice free in early August. This could be in 2020 or 2080. And you said you look at the arctic weather all the time, you would know that claiming 10C 850s didn't show up in most cases is wrong. They showed up quite a bit over the low albedo regions or rocky regions.

near 13c on this sounding.

10C at 70N or so on the Eastern side

12.4C 850s, 15.1C 880mb temps

12.2C 850s

11.8C 850s, 15.1C 890mb temps above 70N

You can check them here if you don't believe me, I found over 40 soundings with over 10C 850s between four different stations on both sides of Greenland up to or further North than 70N. There was probably far more than that.

http://weather.uwyo.edu/upperair/sounding.html?region=np

the gfs archives show 15C popping up twice. I don't think 20C 850s in the future is a pipe dream nor would require MS Paint.

http://www.wetterzentrale.de/topkarten/fsavnnh.html

Most of the scientists in the field would say your claim of luck is uninformed at best, do you have proof to back it up? There are quite a few papers already published on this phenomenom and many more coming out now, have you read them? What do you not agree with that makes you say it's mostly luck?

[nflwxman]

Natural variability is only creating a small negative trend; it's not as if we have natural conditions similar to the Little Ice Age. The PDO didn't go negative until 2007, we had a very strong El Niño in 09-10, volcanic activity has been extremely low, and the solar minimum just started in the last few years, with the only period of really low sunspots being 2008. If this reduced the warming trend to around 0.03C/decade, what can a strongly negative forcing from natural variability do?

I would argue all those forcings you mentioned are the exact reasons why the trend is not strongly

positive. Solar activity is at the lowest level in decades (2008). We just had a string of moderate to strong Nina's. Unless you believe that there will be a stronger negative forcing manifesting itself in the next 50 years, you can bet on significant warming (0.2+/decade). What else can you foresee down the line to dampen the AGW signal exactly (on 30 year timescale).

[nzucker]

I would argue all those forcings you mentioned are the exact reasons why the trend is not strongly

positive. Solar activity is at the lowest level in decades (2008). We just had a string of moderate to strong Nina's. Unless you believe that there will be a stronger negative forcing manifesting itself in the next 50 years, you can bet on significant warming (0.2+/decade). What else can you foresee down the line to dampen the AGW signal exactly (on 30 year timescale).

Well I certainly agree that the -PDO and low solar have a masking effect on the underlying greenhouse gas induced warming. TSI can vary about .1C for the bottom of a cycle, such as in 2008, and having multi-year -ENSO conditions is what plunged global temperatures below average at the beginning of this year and back in 2008. However, we're still in a +AMO, and the coldest global surface temperatures should be when the -PDO and -AMO coincide, which is still probably 15 years away. A longer solar minimum such as the Dalton could also cause greater changes in the climate towards cooling, as could a volcano of VEI 4 or greater. So there are ways that we could dampen the AGW signal more.

[nflwxman]

Well I certainly agree that the -PDO and low solar have a masking effect on the underlying greenhouse gas induced warming. TSI can vary about .1C for the bottom of a cycle, such as in 2008, and having multi-year -ENSO conditions is what plunged global temperatures below average at the beginning of this year and back in 2008. However, we're still in a +AMO, and the coldest global surface temperatures should be when the -PDO and -AMO coincide, which is still probably 15 years away. A longer solar minimum such as the Dalton could also cause greater changes in the climate towards cooling, as could a volcano of VEI 4 or greater. So there are ways that we could dampen the AGW signal more.

Well, if the PDO remains negative and a grand solar min occurs 15 years down the line, we will likely be having the same conversation then about the slowing of a global trend. Only that we will likely be 0.2-0.4 degrees warmer than present at that point.

Ultimately, the longer natural variability masks the signal in negative way, the more surprised we will all be it acts in a positive way towards surface temps.

[csnavywx]

From the IPCC:

http://www.ipcc.ch/p.../tssts-2-2.html

Direct aerosol radiative forcing is now considerably better quantified than previously and represents a major advance in understanding since the time of the TAR, when several components had a very low level of scientific understanding. A total direct aerosol radiative forcing combined across all aerosol types can now be given for the first time as –0.5 ± 0.4 W m^–2, with a medium-low level of scientific understanding. Atmospheric models have improved and many now represent all aerosol components of significance. Aerosols vary considerably in their properties that affect the extent to which they absorb and scatter radiation, and thus different types may have a net cooling or warming effect. Industrial aerosol consisting mainly of a mixture of sulphates, organic and black carbon, nitrates and industrial dust is clearly discernible over many continental regions of the NH. Improved in situ, satellite and surface-based measurements (see Figure TS.4) have enabled verification of global aerosol model simulations. These improvements allow quantification of the total direct aerosol radiative forcing for the first time, representing an important advance since the TAR. The direct radiative forcing for individual species remains less certain and is estimated from models to be –0.4 ± 0.2 W m^–2 for sulphate, –0.05 ± 0.05 W m^–2 for fossil fuel organic carbon, +0.2 ± 0.15 W m^–2 for fossil fuel black carbon, +0.03 ± 0.12 W m^–2 for biomass burning, –0.1 ± 0.1 W m^–2 for nitrate and –0.1 ± 0.2 W m^–2 for mineral dust. Two recent emission inventory studies support data from ice cores and suggest that global anthropogenic sulphate emissions decreased over the 1980 to 2000 period and that the geographic distribution of sulphate forcing has also changed. {2.4, 6.6}

Anthropogenic aerosols effects on water clouds cause an indirect cloud albedo effect (referred to as the first indirect effect in the TAR), which has a best estimate for the first time of –0.7 [–0.3 to –1.8] W m^–2. The number of global model estimates of the albedo effect for liquid water clouds has increased substantially since the TAR, and the estimates have been evaluated in a more rigorous way. The estimate for this radiative forcing comes from multiple model studies incorporating more aerosol species and describing aerosol-cloud interaction processes in greater detail. Model studies including more aerosol species or constrained by satellite observations tend to yield a relatively weaker cloud albedo effect. Despite the advances and progress since the TAR and the reduction in the spread of the estimate of the forcing, there remain large uncertainties in both measurements and modelling of processes, leading to a low level of scientific understanding, which is an elevation from the very low rank in the TAR. {2.4, 7.5, 9.2}

The loss of GRACE hurt here. We still have PARASOL, but the data seems to be limited to open ocean areas only, inhibiting its usefulness.

From: http://www.pnl.gov/m.../PNNL-14537.pdf

Data from this study is only from 2000.

To bridge the gap a bit:

http://www.atmos-che...-1101-2011.html

...which shows increasing emissions again. This makes perfect sense with the rapid growth in China and India's coal usage.

The PDO/temp relationship alluded to shows somewhat of a breakdown in the 90s as the oscillation reached its zenith early on in that decade (and the greatest dT/dt changes were before that).

As for aerosols being overstated, well, I suppose it's possible if the actual effect is on the very low end of the scale. But the distribution of studies and probability distribution of what data we have suggests that is a very low chance.

[nzucker]

Well, if the PDO remains negative and a grand solar min occurs 15 years down the line, we will likely be having the same conversation then about the slowing of a global trend. Only that we will likely be 0.2-0.4 degrees warmer than present at that point.

Ultimately, the longer natural variability masks the signal in negative way, the more surprised we will all be it acts in a positive way towards surface temps.

Why? GISS shows a warming of <.05C/decade since 2002, and the satellites are similar. UAH shows an overall warming trend of .14C/decade since 1979, so even if the long-term trend picked back up we wouldn't warm .4C in 15 years.

[csnavywx]

Why? GISS shows a warming of <.05C/decade since 2002, and the satellites are similar. UAH shows an overall warming trend of .14C/decade since 1979, so even if the long-term trend picked back up we wouldn't warm .4C in 15 years.

The majority of the short-term response from a .5 to 1.0 W/m2 imbalance is on the order of 10-15 years, so I'm not sure where you're getting that from. There's essentially already another ~.5C worth of warming "in the pipeline" in the timeframe you're talking about, minus any strong downward forcing (like that of SO2, etc) and plus Arctic albedo feedback. The loss of perennial sea ice cover plus the GHG response should overwhelm any other foreseeable negative forcing over that timeframe (unless Asia and the developing countries keep growing at their current rates, which seems unlikely over that time span).

[Snow_Miser]

The majority of the short-term response from a .5 to 1.0 W/m2 imbalance is on the order of 10-15 years, so I'm not sure where you're getting that from. There's essentially already another ~.5C worth of warming "in the pipeline" in the timeframe you're talking about, minus any strong downward forcing (like that of SO2, etc) and plus Arctic albedo feedback. The loss of perennial sea ice cover plus the GHG response should overwhelm any other foreseeable negative forcing over that timeframe (unless Asia and the developing countries keep growing at their current rates, which seems unlikely over that time span).

We don't know how much warming "is in the pipeline" as that is determined off of the equilibrium sensitivity to a doubling of CO2, which is highly unknown. The Cloud Feedback is one that the IPCC has even acknowledged is largely unknown.

[Snow_Miser]

Why? GISS shows a warming of <.05C/decade since 2002, and the satellites are similar. UAH shows an overall warming trend of .14C/decade since 1979, so even if the long-term trend picked back up we wouldn't warm .4C in 15 years.

Since 2002, some of temperature slopes are actually negative. HadCruT3 is at a decadal trend of -0.09 Degrees C since 2002, however, to adequately compare ENSO years, one should start at 2001, since the state of the Tropical Pacific was very similar then, almost idential, as it is now. (CPC) Since 2001, the temperature trend on GISS is 0.03 Degrees C per decade, HadCruT3 is -0.06 Degrees C per decade, RSS is -0.05 Degrees C per decade, NCDC is -0.02 Degrees C per decade, and UAH is 0.05 Degrees C per decade. Most of the datasets show a slight negative trend in temperatures over the last 11 years.

[Snow_Miser]

Thank you for sharing that paper - you're right, it is interesting. Using Google Scholar I found several similar papers that support the central hypothesis.

Of course the next question is - what is causing the ozone depletion? Here is a recent paper, Portmann et al 2012, on just that topic that implicates anthropogenic nitrous oxides at the primary culprit. Here is their abstract:

So between anthropogenic GHGs, anthropogenic nitrous oxides, and anthropogenic halocarbons we are really trashing the Earth's atmosphere.

The stratospheric temperatures have increased over the last 15 years, probably reflecting an increase in Ozone Concentrations. This is probably due to the Montreal Protocal banning CFCs, and the sun going into a quieter state overall.

Adding more CO2 to the atmosphere is not "trashing the atmosphere," more CO2 will be beneficial to crop growth.

[csnavywx]

We don't know how much warming "is in the pipeline" as that is determined off of the equilibrium sensitivity to a doubling of CO2, which is highly unknown. The Cloud Feedback is one that the IPCC has even acknowledged is largely unknown.

Paleoclimate data strongly suggests a sensitivity of 3C/doubling with "fast feedbacks" included. This is far better understood than aerosols, which aren't "largely unknown" as you assert here. They are less well understood, but they were understood enough to include in the report. The IPCC used an aerosol forcing of -1.3 W/m2 (direct and indirect effects included). The problem is that the distribution of possible values is skewed heavily towards the upper end, leaving open the very real possibility of a "fat tailed" value. For more information on this type of risk, I recommend Nassim Taleb's Black Swan.

[Snow_Miser]

Paleoclimate data strongly suggests a sensitivity of 3C/doubling. This is far better understood than aerosols, which aren't "largely unknown" as you assert here. They are less well understood, but they were understood enough to include in the report.

We have a very uncertain paleoclimate dataset to know what forcings were causing temperature changes millions of years ago, the magnitude of these forcings, and whether there was more than one forcing creating temperature changes on Earth. We did not have satellites 500 million years ago to know what the forcings were doing at that time. Thus, trying to derive the sensitivity from paleoclimate data is a poor way of trying to determine it.

[csnavywx]

We have ZERO evidence to know what forcings were causing temperature changes millions of years ago, the magnitude of these forcings, and whether there was more than one forcing creating temperature changes on Earth. We did not have satellites 500 million years ago to know what the forcings were doing at that time.

Strawman.

Anyways, paleoclimate data is extremely useful for figuring out what you just denied. Here's a good page:

http://www.ncdc.noaa.gov/paleoclimate-data

[Snow_Miser]

Strawman.

Anyways, paleoclimate data is extremely useful for figuring out what you just denied. Here's a good page:

http://www.ncdc.noaa.gov/paleoclimate-data

Not if we don't know what forcings and the magnitude of these forcings creating temperature changes are.

Are you really claiming that paleoclimate proxies do not have a large error margin?

[csnavywx]

Not if we don't know what forcings and the magnitude of these forcings creating temperature changes are.

Are you really claiming that paleoclimate proxies do not have a large error margin?

Forcings are defined as inputs which change the amount of energy either coming in or leaving the earth system. There are only so many of these. The rest are feedbacks. Solar luminosity changes (which account for about 1 W/m2 over 50My), continent locations (1 W/m2 or less over the past 50 My), and GHGs/atmos composition changes such as changes in CO2.

Please do not put words into my mouth.

Your implication of "ZERO evidence" is incorrect. It is unwise to conflate uncertainty with absence of evidence.

https://wesfiles.wesleyan.edu/home/droyer/web/Beerling_Royer_Cenozoic_CO2_Nature_Geoscience.pdf

The uncertainty is not as large as you seem to imply. It is certainly low enough for this data to be useful in an empirical method. In fact, research using empirical methods has already been conducted.

[ORH_wxman]

The majority of the short-term response from a .5 to 1.0 W/m2 imbalance is on the order of 10-15 years, so I'm not sure where you're getting that from. There's essentially already another ~.5C worth of warming "in the pipeline" in the timeframe you're talking about, minus any strong downward forcing (like that of SO2, etc) and plus Arctic albedo feedback. The loss of perennial sea ice cover plus the GHG response should overwhelm any other foreseeable negative forcing over that timeframe (unless Asia and the developing countries keep growing at their current rates, which seems unlikely over that time span).

So you think we will warm 0.4C in 10-15 years?

I would be highly skeptical of that claim.

[Snow_Miser]

Forcings are defined as inputs which change the amount of energy either coming in or leaving the earth system. There are only so many of these. The rest are feedbacks. Solar luminosity changes (which account for about 1 W/m2 over 50My), continent locations (1 W/m2 or less over the past 50 My), and GHGs/atmos composition changes such as changes in CO2.

Please do not put words into my mouth.

Your implication of "ZERO evidence" is incorrect. It is unwise to conflate uncertainty with absence of evidence.

https://wesfiles.wes..._Geoscience.pdf

The uncertainty is not as large as you seem to imply. It is certainly low enough for this data to be useful in an empirical method. In fact, research using empirical methods has already been conducted.

I know what a forcing is and how it is different than a feedback. Feedbacks are a product of the climate system responding to a forcing.

How am I putting words in your mouth? You made a claim that based off of the paleoclimate record, we can determine the equilibrium sensitivity to a doubling of CO2 to be somewhere around 3 Degrees C. That would have to be a pretty accurate record in order to make such a certain claim.

I admit that my claim of zero evidence was a bit over the top, and my newest edit reflects this change.

The uncertainty seems to be more than you would seem to imply. How do you know that changes in solar luminosity and Greenhouse Gases were the only forcings that were impacting the climate 200,000 years ago? How do you know that a natural internal cycle/GCR cycle did not create a reduction in Cloud Cover by 5%, and that helped to warm the climate up 200,000 ago as well?

[csnavywx]

I know what a forcing is and how it is different than a feedback. Feedbacks are a product of the climate system responding to a forcing.

How am I putting words in your mouth? You made a claim that based off of the paleoclimate record, we can determine the equilibrium sensitivity to a doubling of CO2 to be somewhere around 3 Degrees C. That would have to be a pretty accurate record in order to make such a certain claim.

I admit that my claim of zero evidence was a bit over the top, and my newest edit reflects this change.

The uncertainty seems to be more than you would seem to imply. How do you know that changes in solar luminosity and Greenhouse Gases were the only forcings that were impacting the climate 200,000 years ago? How do you know that a natural internal cycle/GCR cycle did not create a reduction in Cloud Cover by 5%, and that helped to warm the climate up 200,000 ago as well?

I see where you're going with this, so we need to turn to astronomy and a recent CERN experiment. By the way, "natural internal cycles" by definition can only redistribute heat. They do not create or trap it. Cloud cover changes are a response to forcings, such as aerosols, and yes, even GCRs. How big of an effect do GCRs have? We now have a clue, thanks to CERN:

Kirby, et al. 2011

http://www.nature.com/nature/journal/v476/n7361/full/nature10343.html

Taken from RealClimate (http://www.realclimate.org/index.php/archives/2011/08/the-cerncloud-results-are-surprisingly-interesting/):

"So what changes did they show as a function of the CR activity? In going from neutral (shielded) conditions to ambient CR levels typical of the lower atmosphere, the ionisation changed by a factor of 2 to 10 (depending on the temperature – colder conditions are more sensitive). However this is a much bigger change (by an order of magnitude or more) than the percentage change in CR activity over a solar cycle (i.e. ~10-20%). A rough calculation (by way of Jeff Pierce) that takes into account the square root dependence of ion concentrations on GCRs and the neutral nucleation in the CLOUD results, suggests that for average conditions the solar modulation of GCR would impact nucleation by about 1% – rising to perhaps 12% for the biggest changes in GCR seen in figure 2 at very cold temperatures. Thus the nucleation change as a result of real world GCR modulation is going to be much smaller than seen in these experiments, and much less important than the amount of pollutants."

Figure 2 for reference:

[Snow_Miser]

I see where you're going with this, so we need to turn to astronomy and a recent CERN experiment. By the way, "natural internal cycles" by definition can only redistribute heat. They do not create or trap it. Cloud cover changes are a response to forcings, such as aerosols, and yes, even GCRs. How big of an effect do GCRs have? We now have a clue, thanks to CERN:

Kirby, et al. 2011

http://www.nature.co...ature10343.html

Taken from RealClimate (http://www.realclima...ly-interesting/):

"So what changes did they show as a function of the CR activity? In going from neutral (shielded) conditions to ambient CR levels typical of the lower atmosphere, the ionisation changed by a factor of 2 to 10 (depending on the temperature – colder conditions are more sensitive). However this is a much bigger change (by an order of magnitude or more) than the percentage change in CR activity over a solar cycle (i.e. ~10-20%). A rough calculation (by way of Jeff Pierce) that takes into account the square root dependence of ion concentrations on GCRs and the neutral nucleation in the CLOUD results, suggests that for average conditions the solar modulation of GCR would impact nucleation by about 1% – rising to perhaps 12% for the biggest changes in GCR seen in figure 2 at very cold temperatures. Thus the nucleation change as a result of real world GCR modulation is going to be much smaller than seen in these experiments, and much less important than the amount of pollutants."

Figure 2 for reference:

The PDO is a natural internal oscillation, and it can create climate change by changing the amount of global cloudiness by 1 or 2% by altering weather patterns.

Kirkby et al. 2011 did not really prove anything other than the fact that GCRs enhance the nucleation rate, which is really no surprise, considering that GCRs are correlated to the tree ring width, (Dengel et al. 2009) they impact The Diurnal Temperature Range substantially after a Forbush Decrease (Dragic et al. 2011) A link between low latitude precipitation and Earth's Magnetic Field (Knudsen and Riisager 2009) They are highly correlated to precipitation changes (Kniveton and Todd 2001)(Stozhkov et al. 1995) and are highly correlated to atmospheric aerosols (Svensmark et al. 2009).

In fact, while they confirmed a linkbetween the nucleation of particles and cosmic rays, they say that, "

Ion-induced nucleation will manifest itself as a steady production

of new particles that is difficult to isolate in atmospheric observations

because of other sources of variability but is nevertheless taking place

and could be quite large when averaged globally over the troposphere.

However, the fraction of these freshly nucleated particles that grow to

sufficient sizes to seed cloud droplets, as well as the role of organic

vapours in the nucleation and growth processes, remain open questions

experimentally."

Thus, CERN did not confirm the magnitude of the GCR-Cloud effect, but confirmed that the link is there.

Observational evidence has indicated that GCRs significantly influences the atmospheric parameters, and therefore, impacts the Climate.

According to Yu 2002, the GCR Flux has decreased by 5-8% during the late-20th Century, reflecting an increase in Solar Activity, and a natural component to the late-20th Century Warming. Other studies like Lockwood et al. 1999 also confirm this, with a 41% increase in the sun's magnetic activity during the late-20th Century corresponding to a 4% decrease in the GCR Flux during the late-20th Century.